Make LD FLags in Makefile extensible
Make LD FLags in Makefile extensible

Just like the CFLAGS variable, the LDLIBS variable should be
extensible with environment variables.
This is for example required because Debian packages (should be)
built with special hardening flags:
https://wiki.debian.org/Hardening

yabar-dev/yabar,yabar-dev/yabar,geommer/yabar,NBonaparte/yabar